it's hard to understand what you mean with yearly release
It is indeed never a simple rehash of the game that came before it, nor is it fixed around a fixed period of the year, like sports titles or CoD. But battlefield has released a new title every year since 2002
that is, if you count the expansion packs.
But I doubt that should mean we see BF4 next year, for now I'll stick to enjoying bf3 instead of worrying about a sequel